André Villas-Boas hailed Chelsea's re-emergence in the Premier League title race after watching his team beat the leaders, Manchester City, on a dramatic and contentious night that ended with the visiting manager, Roberto Mancini, accusing Ashley Cole of instigating a post-match row between the players in the tunnel.

The Italian, furious that his side had not been awarded a penalty for an apparent trip on David Silva after Mario Balotelli had given them lead inside two minutes, mocked Cole and his Chelsea team-mates after City's first defeat of the season, accusing them of being "lively" after the final whistle because they had beaten one of the division's top teams.

"I don't know what he [Cole] said, I didn't understand it," Mancini said. "But they were really lively because they beat a top team. It's important for them."

Villa-Boas refused to be drawn into an argument, describing claims of a melee inside the tunnel as "unfair and untrue". The Portuguese wanted to focus on a "massive victory" that saw his side cut the gap between them and City to seven points. There was also joy for Frank Lampard who, having started a second match in succession on the bench, got the winner with a late penalty after Raul Meireles had equalised on 34 minutes.

"This was a very good win for the players," said Villa-Boas. "Going 1-0 down so early in the game made things difficult because it gave Manchester City more motivation and more belief, but we showed strong character and did well, especially in the second half.

"Seven points in this Premier League title is nothing, many games will continue to happen, and we believe in our title challenge. But for our title challenge to continue to be alive we will have to continue to be competent. We have to continue to perform. But the talent of this team is not in question."

A fourth win in five matches seemed unlikely for Chelsea after Balotelli, a surprise starter having been reprimanded by Mancini for breaking a club curfew at the weekend, had latched on to Sergio Agüero's cute pass and rounded Petr Cech to score his 11th goal of the season. But Chelsea rallied and, having got back into the game through Meireles's close-range volley, they took full advantage of City being reduced to 10 men through Gaël Clichy's 58th-minute sending-off, for two bookable offences.

Daniel Sturridge's cross was handled by Joleon Lescott and Lampard, having overruled Juan Mata, converted the 83rd-minute spot-kick, 11 minutes after he had come on.

"It's easy to stand aside and let someone else take it but I wanted to do right and win for the team," said the midfielder. "I'm 33 years old but I want to keeping doing well and playing regularly for this club. I know I've got a lot to give. I've got 18 months left here and I'll be here for that long and keep trying my hardest."

For Mancini the most important penalty decision of the night was the one that did not go the way of his side. On 14 minutes José Bosingwa appeared to trip Silva only for the referee, Mark Clattenburg, to deem it a fair challenge.

"There was a friend of mine outside the stadium who saw the penalty, but the referee didn't see it. How did he miss it?" said City's manager. "Maybe because it rained a lot. I do know. We dominated and after the sending-off the game totally changed. But it will change nothing for us. We lost one game but it is a very very long hard season. We didn't deserve to lose but it's finished now."

City's lead over Manchester United remains at two points. The champions will go top if they beat Queens Park Rangers on Sunday, a couple of hours before City host Arsenal.